I don’t think Mormons see the Prophets as “infallible”, so I don’t see the import of quoting Prophets all the time, without also looking at the scriptural basis for the Prophets’ claims.
That is the problem. If you ask 10 different mormons when their “prophet” is infallible, you will get 20 different answers.
Early on in this thread, you will see where ParkerD talked about their “prophet” offering their opinion in relation to blacks and the priesthood. However, their scripture shows that it is doctrinal.
Trying to figure out when a mormon “prophet” is speaking for God is like nailing jello to the wall.
Here is an example of when the vast majority of reasonable, thinking individuals would think that Brigham Young was speaking what God told him. (bolding mine)
If one drop of negro blood meant death on the spot, what do you think it meant for someone with 100% negro blood?
Can you say “Doctrinal Racism”?
"Brigham Young is generally credited with having been responsible for revoking the priesthood and temple blessings from black members of the LDS Church, who had been treated equally in this respect under Joseph Smith’s presidency.[13]
During the Mormon flight from Illinois towards Utah in 1847, Brigham Young received a letter informing him of an inter-racial marriage by the son of a prominent black member, Walker Lewis. The letter was written by William Ivers Appleby, a Mormon elder, who desired to know if interracial marriage was an acceptable practice. Appleby sent the letter to Young at Winter Quarters, Nebraska, but Young was actually in Utah, and therefore did not receive Appleby’s missive until December 1, 1847, when he returned to Winter Quarters. Quite coincidentally, Appleby himself arrived in Winter Quarters on December 2. Young read Appleby’s letter and then had him personally report to Young and the eight apostles who were then in Nebraska.[14] In 1863, Young reported that he said, “Shall I tell you the law of God in regard to the African race? **If the white man who belongs to the chosen seed mixes his blood with the seed of Cain, the penalty, under the law of God, is death on the spot. This will always be so” **(Journal of Discourses, vol. 10, p. 110)."
en.wikipedia.org/wiki/Brigham_Young
Again, do some research.